Motoring Notes

Motorway Centre Reservations The growth of high speed roads during the last 20 years brought increasing demands for the installation of barriers to improve traffic separation and, more recently, to prevent crossover accidents on motorways. Space has previously been devoted in this column to crash barriers of various types developed by the Transport and Road Research Laboratory but "product improvement" is worthy of further comment. During the course of early work on crash barrier development emphasis was placed on the use of hedges to retain vehicles which left the carriageway. Naturally it took some time to grow the various hedges to the point where they could be used for testing and after having waited for so long scientists were most disappointed with the results. None of the experimental hedges was capable of holding even a small motor car and most had no marked effect even on reducing the speed of the vehicle. The idea was scrapped and subsequent work concentrated on engineering principles to find an answer to the problem. British research led the world in the aspect of safety engineering and although different types of answers were found the tensioned steel beam barrier is virtually standardized now on British motorways. There are some examples of specially formed kerbs to act as deflectors and the wire rope barrier, possibly the best, but also the most expensive, is in use in Canada, Switzerland and on parts of the M62 motorway. The early trial section of barrier on the M I motorway produced remarkable savings in fatal and serious injury crossover accidents at a time when accident figures generally and on the "control" section rose by about 30%. Some motorway patrol officers predicted rises in accidents due to collision with the barrier as it was thought that many instances occurred of drivers using the centre reserve as an escape route and these incidents rarely came to the notice of the police. Their fears were supported by the trial section figures but lives were being saved by the prevention of crossovers and barriers became almost standard features. A more recent extension on the M I near London has antidazzle slatted fencing fitted above the barrier to further improve driver comfort and safety. An interesting formula has been found in order to decide optimum sizes and angles for fitting anti dazzle slats but the full results of this particular experiment will not be


Motorway Centre Reservations
The growth of high speed roads during the last 20 years brought increasing demands for the installation of barriers to improve traffic separation and, more recently, to prevent crossover accidents on motorways. Space has previously been devoted in this column to crash barriers of various types developed by the Transport and Road Research Laboratory but "product improvement" is worthy of further comment.
During the course of early work on crash barrier development emphasis was placed on the use of hedges to retain vehicles which left the carriageway. Naturally it took some time to grow the various hedges to the point where they could be used for testing and after having waited for so long scientists were most disappointed with the results. None of the experimental hedges was capable of holding even a small motor car and most had no marked effect even on reducing the speed of the vehicle. The idea was scrapped and subsequent work concentrated on engineering principles to find an answer to the problem. British research led the world in the aspect of safety engineering and although different types of answers were found the tensioned steel beam barrier is virtually standardized now on British motorways. There are some examples of specially formed kerbs to act as deflectors and the wire rope barrier, possibly the best, but also the most expensive, is in use in Canada, Switzerland and on parts of the M62 motorway.
The early trial section of barrier on the M I motorway produced remarkable savings in fatal and serious injury crossover accidents at a time when accident figures generally and on the "control" section rose by about 30 %. Some motorway patrol officers predicted rises in accidents due to collision with the barrier as it was thought that many instances occurred of drivers using the centre reserve as an escape route and these incidents rarely came to the notice of the police. Their fears were supported by the trial section figures but lives were being saved by the prevention of crossovers and barriers became almost standard features.
A more recent extension on the M I near London has antidazzle slatted fencing fitted above the barrier to further improve driver comfort and safety. An interesting formula has been found in order to decide optimum sizes and angles for fitting anti dazzle slats but the full results of this particular experiment will not be evaluated until next year. By that time it is hoped that assessments will have been made on the effects of the screen in reducing night accidents. Data will also be available on the impressions and reactions of drivers, the cost of maintenance, the cost of replacing sections damaged in accidents and the effect on severity of accidents involving the slats. Now a further development is finding its way onto motorways and in one sense we seem to have turned full circle. The Department of Transport has planted shrubs experimentally on the central reservations of short lengths of the M27 motorway in Hampshire and the Ml motorway in Northamptonshire and Leicestershire. It is hoped that the planting will add interest to driver's and passenger's views and give a feeling of separation from opposing traffic, particularly at night when headlamps are in use.
A little over five kilometres of the M27 in Hampshire, between Cadnam and Chilworth have been planted with a mixture of shrubs including thorn, dog rose, hazel, field maple, dogwood, broom, blackthorn, privet guelder rose and snowberry. On the M I there has been similar planting on a ten kilometre length between Crick in Northamptonshire and Lutterworth in Leicestershire.
The idea is not new of course as many dual carriageways have long had trees and hedges along central reservations which provide very restful driving at night, cutting down or eliminating the distracting glare from opposing headlamps. Unfortunately, such growths also created hazards as they tended to restrict the views of drivers approaching or attempting to cross over at intersections and junctions. Happily this drawback does not apply to British motorways.
Most subscribers will be aware that growing conditions on central reservations of our motorways are difficult and to combat this one third of the 135,000 shrubs were grown in containers during the hot dry summer of 1976 so that transplanting could be carried out with little root disturbance. The remaining plants were normal bareroot nursery stock. Due to the lack of space in the standard central reservation, which already has a safety fence and drain, the planting has been somewhat restricted to form a one metre wide hedge.
With increasing interest being shown in psychological aspects of the driving task and a greater awareness of the need to preserve our natural environment we have seen substantial design improvements in successive motorway building programmes compared with the earlier examples. This latest addition is a welcome advance.

NEW COMPONENTS Electronics
Since writing in detail about the Lucas electronic ignition system a separate system marketed by Kenlowe Accessories & Co Ltd, has come to notice. Although I have not yet had an opportunity to test this ignition it is worthy of mention as it retails at £8 less than the Lucas unit and also features a built in timing light for accurate engine tuning. The Kenlowe unit utilizes the original distributor body with rotor arm points and condenser removed. A reed switch trigger head is fitted in the position formerly occupied by the points and a new rotor arm with integral ring magnet placed in position before refitting the distributor cap. The electr6nic circuitry is built into a remote box fitted to a convenient point in the engine compartment. Wiring appears simple, fitting rapid and the unit should provide improvements in power and fuel consumption.
There can be no doubt that the electronics industry intends to become more involved with future road transport and already this year Lucas is introducing a new range of electronic distributors to substantially reduce costs. These new units incorporate the latest technology in integrated circuit and thick film design. They are more rugged in the car environment (and therefore more reliable) and at the same time more compact in size and less costly to produce. The pick-up module of the new magnetic variable reluctance system transmits to a separately housed power amplifier sited remotely from the distributor. This facilitates cooling of the circuitry and allows improved access if servicing should prove necessary. The unit retains for the present the conventional mechanical centrifugal automatic advance components and also the vacuum adjustment facility linked direct to the exhaust manifold. Electronics technology however is advancing strongly and is likely to replace these and other functions in the motor vehicle. Electronics reliability is now proven and scope for employing the special advantages of these types of components is enormous.
The next logical step in ignition development is the complete elimination of the distributor as we know it (which has so far remained substantially unchanged for three quarters of a century). The present mechanical method of altering the timing will be replaced by electronically governed advance and retard. A digital timing device is under development by Lucas which will vary the ignition timing according to engine speed and load. This might also incorporate features by which ignition timing may be "trimmed" to accommodate changes in engine temperature, barometric pressure and other environmental factors.
This kind of electronic progress in the motor industry also opens the field of activity for an escalation of the use of fuel injection. Lucas already has a suitable large scale integrated circuit which makes possible a digital control system providing a degree of sophistication which 'cannot be satisfactorily achieved using analogue techniques. The closer matching of fuel requirements obtained from the digital system will give an improvement in fuel economy and will further reduce the level of toxic gases emitted from the exhaust. Direct measurement of the airflow by the new system will provide correct air/fuel ratio settings under all running conditions. An air meter will feed signals to an electronic computer. Th is will be processed to gether with other data co vering speed, temperature, atmos pheric pressure a nd some other factor s in order to instantl y adju st the the fuel injection to its o ptimum sett ing. An additional so phistica tio n will be a special senso r to feed back a signal to the computor giving a readin g of the oxygen level in the exhaust pipe. Th is evaluation of the qu al ity of the exhaust gas allow s further co rrectio n of the fuel flow to the eng ine to give even better performance a nd more stringent control of exhau st emission s.

Fuel Pump
Th ose Forces which ha ve been operating fuel injecti on patrol ca rs in the past may have experienced problems with vapour lock in the fuel lines during hot weather. AC Delco has no w produced an in-ta nk pump which help s con siderably towards a solutio n to th is problem. Submerged in the fuel tank itself the pump is operating " In Tank" Electr ic Fuel Pump in a relatively cool environment which eliminate s all pump suction losses and reduces the tend en cy for fuel to va pourize in the pump. Petr ol on its way to the cal burett or/injector s is under pre ssure at a ll times and thi s reduces the risk of va po urization in the fuel lines. A further sophi sticat ion is that the control switch for energizing the pump during sta rti ng a nd when the engine is runn ing is actuated by engine oil pre ssur e. Wh ilst thi s means th at the pump ceases to operate if the eng ine oil pressure drops thereby prote cting the engine from damage, it also means that the fuel pump will not operate until the engine oil pump has built up sufficient pre ssure to actuate the switch and this could lead to difficult starting under certain conditions. Field tests show that this pump has an estimated running life of 3,000 hours.

Light ing
Lighting devel opment has been fa irly static in the last two years but Forces using long range spot lamps for vario us purposes may like to know of improvements in the 702 range produced by Marchal. The 702 long range lamp with standard 55w bulb produces 308,000 candle power which is some 10 times the output of a normal headlamp. The significant advance is that a lOOw bulb can now be fitted to this lamp to give a quite extra-ordinary 365,625 candle power from the one unit. This bulb is also available for fitting to the 709 driving and 700 fog lamps, providing relative improvements in light output.

Battery
A further development by AC Delco which may prove of considerable value to Police fleet operators is the Freedom maintenance free battery. This unit uses special plates with a new grid chemistry and the plate area is carefully balanced with the proper amount of electrolyte reserve so that it will not run out of fluid. The battery Delco Freedom Battery never needs checking for water or topping up, cleaning or servicing. The cover is sealed on and thus contamination is avoided. The battery is designed to last for 300,000 miles but some of those batteries which are at present in service are approaching 500,000 miles without showing signs of failure.

Engineering -Clutch.
Many fleet engineers will know that this component is subjected to considerable misuse in the Police vehicle environment and is a regular cause of police vehicle down time. Automotive Products Ltd seem to have achieved a break through with a new design of diaphragm spring clutch, the Borg & Beck "DST" clutch. A new method has been found of locating the diaphragm spring in the cover pressing. This gives improved support for the spring when the clutch is operated, resulting in lower pedal loads and a more consistent performance, together with improved durability. Turnover tabs in the cover are used to locate the diaphragm spring and these replace the more usual rivets, sleeves and fulcrum ring support plate previously used, thus reducing the number of components from 23 A completely new method of locating the diaphragm spring within the cover pressing. of the Borg & Beck DS'Lclutch results in improved efficiency and durability, whilst raw material savings and simplified production combine to give these benefits without added cost. Conventional clutch design employs rivets, sleeves, and a fulcrum ring support plate to locate and support the diaphragm spring and associated fulcrum rings in the cover pressing. In the DST clutch these are eliminated. the spring and fulcrum rings being located by twelve "turnover'ttabs in the cover pressing. These are shown (top left) prior to the first stage of cover assembly. The fulcrum rings and DIS spring are then assembled into the cover, and the tabs are turned-over in two pressing operations to locate the spring and provide highly effective support for the fulcrum rings (bottom left). Finally, the drive straps are rivetted to the cover to locate the pressure plate and complete the assembly.
to only four and greatly simplifying assembly. In addition, the DST clutch is 27 % lighter than conventional clutch covers giving a considerable raw material saving. These two reductions together mean that the cost of the new clutch will be lower, but it has been designed to be completely compatible with the existing driven plate.

Engineering -Overdrive
Some Chief Officers may still be operating load carrying vehicles over long distances, for example, on motorways. One of the drawbacks of this type of operation has always been the low gearing of commercial vehicles which has never been entirely suitable to the police requirement of bulk load carrying with little weight. The GKN Group now has something of an answer with development of a heavy duty overdrive unit for use on vehicles up to 5.5 litres capacity. This unit will fit most British vans, including the Ford Transit, Leyland Sherpa, and Dodge and Bedford light vans. Under test the overdrive has consistently shown savings in fuel consumption up to 18%and operates in the ratio of 0.7721 : 1.
A further advantage is that it is suitable for fitting to both manual and automatic transmissions.

Engineering -Alloys
Investigations are being made into the use of low weight metals .in propeller shafts, replacing steel with aluminium alloy parts. Weight reduction is an advantage and these investigations into light weight propeller shafts also seem to be producing spin-off benefits. Improvements to this part of the transmission will be reviewed in the future.
A new plant has recently been commissioned by the GKN Group and becomes Europe's first for the manufacture of pressure die castings in steel and high cost alloys. The techniques in use have brought stainless steel and high cost alloy components within reach of the accountants ideals for vehicle manufacturers. The excellent finish obtained from the process provides additional cost savings through a reduction in component machining prior to production assembly. In the long term lower cost alloys and conventional carbon steel components will be produced at reduced costs. Transport Managers should be aware of these improvements in order to obtain the best value for money and make the best use of public funds.

ELECTRONIC IGNITION
Two years ago I mentioned, briefly, in this column the new replacement electronic distributor produced by Joseph Lucas Limited. Although this type of ignition has been extensively used during the last decade on high performance racing car engines, it has only recently been produced as replacement equipment for normal road vehicles and it seems likely to be several years before it will become original equipment on a wide range of motor cars (although it is already fitted as standard to the new Rover 3500).
The common distributor as a means of producing a high tension current to the plugs of the engine has been with us in much the same form for as long as we have had multi-cylinder engines, and ignition problems form a major part of any list of breakdown causes. No matter how effective the condenser, no manufacturer has yet found a way of eliminating sparking across the contact breaker faces and this problem progressively alters the contact breaker gap, until at 6,000 miles the points are generally ready for renewal and the engine has to be retimed.
The new Lucas 45DE distributor is a fully electronic replacement for the existing distributor. It is simply a matter of removing the clamp bolt holding the existing distributor, disconnecting the wires, replacing it with the new distributor, connecting up and timing the engine. Once in place the unit need not be touched again during the life of the car and this facilitates sealing if necessary to overcome dampness problems, which are well known on certain models. Unlike the conventional distributor the electronic unit has no points and therefore no contact breaker gap. It cannot bounce at high revs causing an engine to misfire and there is no danger of arcing at low revs, which often makes for poor starting and a weak, irregular tick-over. The timing of the engine is always absolutely in accordance with manufacturers recommendations and should therefore produce optimum performance throughout the life of the engine.
The main features are a timing rotor, pick up module and an amplifier module.
The timing rotor is mounted on the distributor drive shaft beneath the rotor arm in the position occupied by the cam in a contact breaker system. This rotor takes the form of a plastic drum with ferrite coupling rods (4, 6 or 8 according to the number of engine cylinders) embedded in its periphery. The pick-up module, mounted on the bearing plate assembly has an "E" shaped ferrite transformer core with primary and secondary windings, enclosed in a plastic housing.
The amplifier module contains an oscillator, a smoothing circuit, an amplifier, and a power transistor which is connected in the ignition coil primary circuit. The oscillator, smoothing circuit and amplifier assembly consist of discrete components mounted on a printed circuit board and encapsulated for protection.
When the ignition is switched on and the engine is cranked, a ferrite rod in the timing rotor passes across the face of the pick-up "E" core causing the oscillator to break into high frequency operation. The output from the oscillator, is smoothed and fed into the amplifier to switch off the output power transistor. Since this transistor is connected in the ignition coil primary circuit, primary current is interrupted each time a ferrite rod passes across the face of the pick-up module, and a high voltage is induced in the secondary winding of the ignition coil. This high voltage is then distributed to the appropriate spark plug via the rotor arm and cover electrodes in the usual manner.
Lucas claim that the new distributor will provide improved starting, consistent sparking performance, better performance at high revs, increased reliability, reduced servicing costs and the likelihood of significant fuel economies. This distributor is at present under test in the vehicle fleet of my own force and results so far are encouraging. I hope that it will be possible to give some long term evaluations in connection with fleet use in a future edition.
In order to evaluate the claims made by Joseph Lucas Limited J fitted one of these units to my own car, an Allegro 1750 Sport, so that I could check accurately any noticeable changes. I was a little surprised to find that the car immediately felt much more lively and the engine sounded sweeter, tick-over was smooth and regular at just under 500 rpm, and the engine revved freely through to its limit at 6000 rpm. Torque seemed perhaps slightly improved but this cannot be confirmed as meter readings were not taken. The most extraordinary change came in the fuel consumption which instantly improved by four miles per gallon. So I am monthly achieving a substantial cost benefit which helps to offset the original purchase price of £30. Starting has become easier and since this ignition was fitted I have not yet found it necessary to use the choke, although electronic tuning equipment shows that the combustion mixture is at the correct ratio of fuel/air. With my annual milage in the region of 12000 miles the improvement which I have gained on my car should result in a saving of about £40 per annum in fuel costs, so that I will recover the cost of fitting the unit within nine months. An additional benefit is a saving of approximately £1.50 per service (at 6000 mile intervals) for the cost of a new contact breaker set and mechanics time in fitting it. If these series of savings become apparent in the evaluation of vehicles within the Avon and Somerset Constabulary fleet we could assume substantial savings in vehicle running costs. However, it is too early at this stage to assess the degree of change applicable to various models.
Nevertheless, it may be worthwhile for contributors to purchase a unit for a private vehicle as it should be possible to recover the cost without difficulty.
From my own experience with this component I am quite satisfied that claims made by Joseph Lucas Limited are justifiable and I shall fit this distributor to my next car when the time comes for a change.

Windscreen Glass
I have discussed this subject before in this column and have always been of the view that laminated glass is a safer type of windshield than one produced from toughened glass, but some recently published research by the Transport and Road Research Laboratory has tended to balance the two types. Unfortunately the matter is not too simple as there are two types of laminated glass currently in service. The newer one being constructed from thin toughened glass layers around a plastic inter-layer. This is a new product, barely in production, but tests suggest that it may prove safer than either the toughened windscreen or the more usual type of laminated windscreen.
Toughened windscreens are fitted as standard to about 90 % of cars in use in this country and when this glass breaks it shatters producing fragments rather than the jagged slivers produced by breakage of untreated glass. When the toughened windscreen shatters (and it may do so without warning) it becomes virtually opaque although most versions now include a relatively clear vision zone for the benefit of the driver. In accident situations glass remnants usually remain embodied in the lower edge of the windscreen and very serious facial injuries can occur when the head of an occupant strikes this surround. On the other hand laminated windscreens may suffer a certain amount of damage in normal service, but are rarely so badly damaged that they present a hazard or prove to be more than a minor inconvenience. A damaged laminated screen can usually wait for replacement at a convenient opportunity whereas a shattered toughened screen is utterly destroyed and requires immediate replacement to render the vehicle at least comfortable, and at most, safe to drive.
The research has shown that shattering of a toughened screen rarely presents serious problems and there is still sufficient visibility to bring the vehicle safely to rest. Additionally, the number of accidents known to be caused or preceded by a shattered toughened windscreen is so small as to be statistically insignificant. Similarly, the incidence of injury is extremely low (this relating to injuries caused by random shattering and not including those in accident situations).
So far as accidents are concerned the windscreen becomes much more dangerous, particularly as a toughened windscreen will shatter both under impact and when subjected to twisting forces as a car body buckles.
In a survey of unbelted front seat occupants seriously injured, the high figure of 17% suffered head injury due to the windscreen, although no case of fatal injury could be attributed to windscreens. Injuries of various types were apparent whichever screen was fitted and comment is made that surveys showing lower rates of injury attributed to laminated glass did not generally relate to British cars and conditions. The incidence of injury caused by windscreen glass is many times lower when a seat belt is worn in addition to the fact that wearing of a seat belt generally halves the over all risk of serious injury. The percentage was so low that windscreen related injuries to occupants who are wearing seat belts is no cause for serious concern.
It seems so far from research that the most significant benefits are to be obtained from changes in vehicle design rather than windscreen construction design until there is a significant technological break through. If occupant restraint can be improved, forward pitching of the body can be overcome, and recessed lower windscreen edges are used, the main risks of serious facial laceration and injuries will be removed. Similarly, use of the improved laminated windscreen may also be effective but further work is required on this aspect.
The general use of seat belts and improved vehicle design should so reduce the possibility of injury that the choice amongst different types of windscreen can be made more realistically on cost con-sideration. At the present time a laminated windscreen initially costs about twice that of a toughened screen, with replacement cost being about 50 %higher.
It therefore seems that despite the publicity of windscreen manufacturers and encouragement to use laminated windscreens the toughened glass screen is equally as good provided the occupant wears a seat belt at all times.